The invention relates to a composition containing fine solid particles such as inorganic and organic pigments, synthetic polymers and the like, all of them held in an encapsulation or dispersed in a matrix whereby the encapsulation or the matrix consists of a homogeneous mixture of cellulose, tertiary amine oxide, water and, if necessary, other components.
Dispersions of solid particles such as pigments are needed for a wide variety of applications. A significant application is for example the mat-finishing of cellulose filaments.
It is practically impossible to distribute solid particles such as pigments, e.g., titanium dioxide, directly and uniformly into a spin mass. This applies also to the manufacturing of cellulose filaments according to the so-called NMMO process, a process whereby cellulose is dissolved in a mixture of N-methylmorpholine-N-oxide, water and, if necessary, additional components and is further processed into filaments by a method known per se. However, attempts to directly stir the pigments into the spin mass result in agglomerations. Therefore spinning disturbances are automatically programmed in. In addition uniformity of the filaments obtained suffers.
For this reason, a preventive measure is taken that results in the production of appropriate suspensions or pastes, i.e., masses containing a considerable portion of the pigment or other solid particles to be distributed, and the spin mass is doped with these pastes or suspensions.
A disadvantage of this process in the prior art is that on the one hand it is very laborious to manufacture such pastes and suspensions, and that even with extensive kneading and stirring the agglomerations of the solid particles cannot be fully destroyed, therefore making it necessary to filter the suspensions once again. On the other hand these processes use emulsifiers or stabilizers, which firstly should ensure a better distribution of the particles in the paste or suspension and secondly should improve the stability of the suspensions or pastes. Despite all of these efforts, signs of separation, sedimentation or reagglomeration continue to appear during storage so that the paste or suspension is no longer homogeneous, possibly leading to irregularities in the manufacturing.
Additionally, during the washing of the filaments, films and the like, which were manufactured using such pastes or suspensions, the emulsifiers and other additives are mostly washed out therefore further polluting the washwater so that additional problems occur during the reprocessing of the washwater and the solvent, especially the NMMO.
For this reason there is still a need for fine, dispersed or dispersible solid particles which do not possess the aforementioned disadvantages, can easily be manufactured, and can furthermore be employed in various applications.